Capacitive touch units have advantages of accurate positioning and agility, and the capacitive touch units have been applied in numerous fields. The capacitive touch units are divided into a self-capacitive type and a mutual-capacitive type, and the mutual-capacitive type touch units can realize multipoint touch, so that the mutual-capacitive type touch units become a mainstream in the market and a development trend in the future.
Mutual-capacitive type touch screens are divided into two structures of an on-cell mode and an integrated mode, and an integrated type mutual-capacitive type touch screen (also called as an in-cell mutual-capacitive type touch screen, short for an in-cell type touch screen hereinafter) is formed by integrating touch units between an opposed substrate and an array substrate of a display panel. An on-cell type touch panel is formed by laminating touch units on a display panel, so that a thickness and a weight of the whole display device are inevitably increased, and the light transmittance is decreased, which are not meet the requirements of the development trend of thinness and lightness of the current display device. In a case that the capacitive type touch units are applied to the in-cell type touch screen, the touch units of the in-cell type touch screen are integrated into the display panel, the in-cell type touch screen has obvious advantages of reducing the thickness of the display device and improving the transmittance, and the lightness and thinness effects of the display device can be realized while the touch control function is realized. However, whether the on-cell mode or the integrated mode, a capacitance between the touch electrodes in the touch unit is apt to be interfered by an electric field in the display panel, as a result the signal noise ratio of an output signal is lower, the signal noise ratio of a touch inductive signal output by the whole touch unit is also lower, and further the precision of touch recognition of the touch unit is lower.